Abstract

Bariumtitanatesingle crystals had been placed in NaOH solution to deposit hydrogen on their electrodes through the electrolysis of water. Two kinds of time-dependent changes in dielectric properties of the single crystals were observed: One occurred in the course of hydrogen deposition and the other lasted for a long period of time after the deposition. The diffusion of hydrogen and in and out of the single crystals may be the cause for the changes. This hydrogen-related dynamic dielectric behavior clearly shows that hydrogen is an important mobile ion other than oxygen vacancy in perovskite-type lattice. Extra attention should be paid to the role of hydrogen in time-dependent property changes, including resistance degradation and ferroelectric aging, of perovskite-type ferroelectric titanates.